High-pressure metered fuel ejector for internal-combustion engines



May 18 1926.

G. A. BELL HIGH PRESSURE METERED FUEL EJECTOR FOR INTERNAL COMBUSTIQN ENGINES FiTed Jan '7 i924 mama/ll? pressure a metered The elimination of working timed;

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Patented May 18, 1926.

UNITED STATES) "5 BELL, or SAN FRANCISCO, CALIFORNIA.

GUY A.

PATENT QF-FICE.

Application filed January 7,1924. Serial No. es4,9o5.-

The present invention relates to improvements in fuel-injectors for that type of internal combustion engines in which an air charge is first admitted to the engine cylin- 5. der and there compressed to a degree sufficient for the generation of a temperature high enough for the ignition of a fuel charge, afterward injected'thereinto under high pressure.- i i A principal object of the invention is the provision of means for supplying, under pressure of high and uniformally' maximum character, a measure of fuel and withdrawing therefrom while under this maximum portionto an accumulator chamber to be therein trapped awaiting a lowered pressure without for its injection into the combustion chamber. 1 Other objects sought tobe attained are: parts for the injection of the fuel; a thoroughly atomized fuel at the instant of injection; a fuel heated through compressive action prior to injection; and a fuel injection automatically The invention comprises a fuel'pump of the plungertype driven from an eccentric on theicrank-sha'ft and communicating with a fuel supply reservoir under pressure by a valvecontrolled passage, and an ejector com prising a valve-controlled receiving chamber, and 'means of communication respectively with the fuel pump and the fuel-supply reservoir.

telescopic shell 'The accompanying drawing, forming a part of this specification, represents a vertical sectional view of a preferred embodi ment of my invention, inwhich are shown the internal construction of both 'pump and injector, the line of communication there between, and the eccentric drive for the particularity, 1 indicates the crank-shaft to which is secured an eccentric 2 by means of a key 3, 4 a ball race, 5 peripheral surface of eccentric 2 bearing against and operating to lift the valve-lift 6 adapted for movement in guide 7, 8 spring-seat carried by lower end of plunger 9,9 fuel-return passage for pressure relief, 10 spring operaing to keep valvelift 6 in contact with the peripheral surface 5 of the eccentric 2, 11 packing gland nut, 12

serving as ameans for setting-up packing 13 and affording upper seat through a valve-controlled accumulator cham- 6, cause a return-movement of for spring 10, 14 governing valve, 16 ball-check held on seat by springol'f, 18 line from fuel reservoir to pump, 19 by-pass' from pump to fuel line 18 through which ducted, 2O detached, divided and spaced stem of valve 15, 21 and 22 spring-seats borne by respective sections of stem 20, 23 and 24 fashioned axial-extremity supports for stem'20, 25 means for the adjustment of pressure relative to stem 20, 26 lever wheremeans, 25 is" turned, 27 packinggland nut, 28 packing, 29 line connecting pump and ejector 30 ejector'housing, 30 auxiliary chamber in ejector housing, 31 needle-valve stem resting on seat at lower pressure-relief is conend of tip 32, this tip being held in place by packing-gland nut 33, 34 der borne by stem 31 and serving for lower seat for spring 36, 37 packing-ring, 38 pack- 1ng, 39 by-pass leading from fuel-recelving chamber 40 to accumulator chamber 41, 42 accumulator check-valve held on seat by spring 48, 44 ejaculatory duct leading from the accumulator chamber 41 to and along the side .of the lower end of the needle-valve stem 31 to and communicating 'with the radially disposed nozzle-ducts 45.

I n operation, assuming as shown the pump at the limit of its out-stroke, the plunger 9 will have lifted valve 15 from its seat, bringing the fuel-return passage 9' borne by the plunger 9 as a relief conduit into registration with the mouth of the line'29 and also by opening a line tween, the injector and the through which pressure may be withdrawn this, the action of eccentric 2, in conjunction with that the spring 10 permitting the seating of valve the pressure of spring 22' stem 20, the which actions contributing to produce a vacuum in the the upper end of plunger 9, the suction of which draws in through valve 16- a measure of fuel to be afterward subjected to compressive force, upon the return stroke of plunger 9, and driven into the receiving chamber 40 and thereafter, upon an increase of -'pressure, into the accumulator chamber 41, w ere it is trapped and retaineduntil a condition or relieved pressure has been again reached, when it is e ected through the duct 15 through in communication with the by-pass 19, thereof lowered "pressure he fuel reservoir upon the valve-lift plunger 9,

exerted upon thepacking, 35 shoulfuel line adjacent 44.- to the nozzle ducts 45 and therethrou'gh thoroughly atomized, to the combustion? chamber. It is to be observed that the fuel-pressure of receiving-chamber 40 increasedby that of the tension of spring 36 is great-erin one direction upon the needle-valve stem 31, than is that of the trapped fuelcharge in theopposite direction, this serving to seat valve and seal perfectly against fuel leakage through nozzle until release of back pressure. v

Having thus described my invention, I claim. and desire to secure by Letters Patent: 1. In a device of the character described,

the combination with a fuel pump,- of means for trapping a metered fuel charge under pressure as received from a fuel pump, said means comprising an ejector having an auxiliary pressure chamber and a resilientwalled, valve-controlled accumulator chamber, a receiving ehamberbearing a springcontrolled valve-stem, a by-passport connecting said accumulator chamber with said receiving chamber, an ejaculatory duct leading from said chamber accumulator chamber to said auxiliary chamber, a com-- pressible elastic packing member in said auxiliary chamber surrounding said valvestem said resilient-walled accumulator cham her, said auxiliary chamber and said packing member. co-acting to accomplish the fe'jeetment of said metered'fuel'charge from the "ejector nozzle upon the lowering of pressure without-{said accumulator chamber and the shutting eff of the fuel supply.

2. In a device-of the character described, the combination 'With a fuel pmnp, of a means for tapping a metered fuel charge under pressure as received from said fuel pump, said means comprising an ejector having a nozzle and an auxiliary pressure chamber anda resilient-Walled valve-controlled accumulator chamber, a receiving chamber bearing a spring-controlled valve-stem, a bypass port connecting said accumulator chamber With said receiving chamber, an ejaculatory duct leading from said accumulator chamber to said auxiliary chamber, a com-- pressible elastic packing member in said auxiliary chamber surrounding said valvestem, said resilient-walled accumulator chamber, said auxiliary chamber and said elastic packing member co-acting, upon release of pressure in said receiving chamber, above said valve-stem, to accomplish the ejectment of said metered fuel charge, through said ejector nozzle, upon the lowering of pressure Without saidaccumulator chamber and the shutting ofi of the fuel supply. 

